The law of cosine or cosine rule in trigonometry is a relation between the side and the angles of a triangle. Suppose a triangle with sides a, b, c and with angles cosC.

The following formula is used to find the angle j is;

$\rm j^2 = h^2 + i^2 -2hicosC$

Triangle HIJ has side lengths h=12, i = 17, j = 7.

Substitute all the values in the formula;

$\rm j^2 = h^2 + i^2 -2hicosJ\\\\(7)^2=(12)^2+(17)^2-2 \times 12 \times 17 cosJ\\\\49=144+289-408cosJ\\\\144+289 -49 =408cosJ\\\\384 =408cosJ\\\\cosJ=\dfrac{384}{408}\\\\cosj = 0.94\\\\J =cos^{-1}(0.94)\\\\J=19.8$

Hence, the measure of angle J is 19.8°, and the correct option is D.

Learn more about law cosine here;

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3 0

2 years ago

Find the area of a circle with a radius of 6 centimeters. Round to the nearest tenth

coldgirl [10]

Answer: 113.1 cm^2

Step-by-step explanation: The formula to find the area of a circle is 3.14r^2. R stands for radius which is 6 in this case so just plug that in for R. 3.14(6)^2=113.1

8 0

3 years ago

Which of the following is true for this graph? <br><br> Will give brainliest to correct answer.

Contact [7]

The answer is A. Slope is rise/run. According to the graph, you can trace out and see that it rises 1 and goes to the right 4 times. This means that it has a positive slope of 1/4. And the line crosses the y intercept at y = 3

So answer choice A is correct.

7 0

3 years ago